in an electric circuit 3 bulbs of raring 40W,60W,100W are connected in parallel .in which bulb the brightness will br maximum and resistance minimum?

Asked by farzul hazan C.S | 14th Jul, 2013, 06:45: AM

Expert Answer:

Since, all the bulbs are usually rated at common voltage, V
Let R1, R2 and R3 be the resistances of the 3 bulbs
 
P1 = 40 = V^2/R1
R1 = V^2/40
Similarly, R2 = V^2/60
R3 = V^2/100
 
Hence, the resistance would be minimum for R3. 
 
Also, since the resistors are connected in parallel, their power would be same as the given power wattage. 
 
Hence, 100W bulb will the brightest of the 3. 

Answered by  | 14th Jul, 2013, 06:13: PM

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